vi) If the subject is female and of childbearing potential, she agrees to use a medically acceptable form of contraception, and not become pregnant for the duration of the study. A woman is considered of childbearing potential unless post-menopausal or surgically sterilized. Female patients of childbearing potential must use either: (1) contraceptive pill or IUD or depot hormonal preparation (ring, injection, implant); and/or (2) a barrier method of contraception such as diaphragm, sponge with spermicide, or condom.